| Autor: |
Ru Ju Wang, Ji Fang Wang, Fengying Li, Ting Zhang Deng, Hong Chen, C. Q. Jin |
| Rok vydání: |
2003 |
| Předmět: |
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| Zdroj: |
Solid State Communications. 127:47-50 |
| ISSN: |
0038-1098 |
| DOI: |
10.1016/s0038-1098(03)00413-7 |
| Popis: |
Using pulse echo overlap measurement, the elastic behavior of amorphous carbon has been studied at ambient and low temperatures. The smaller ratio BIG of the bulk modulus to shear modulus and smaller Poisson's ratio sigma at room temperature indicate that there is an intrinsic stiffening of transverse acoustic phonons in the amorphous carbon. The acoustic velocity and attenuation for longitudinal modes have been measured between 2.1 and 300 K at three frequencies of 7, 21 and 35 MHz, respectively. Their frequency and temperature dependence are observed. The elastic constant C-11 increases with decreasing temperature and show enhanced stiffening at low temperatures. In the 130-220 K region, the abnormal change and effect of longitudinal velocity and attenuation with temperature and frequency, and a phase transition associated with structure relaxations are discussed. (C) 2003 Elsevier Science Ltd. All rights reserved. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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